Antenna lead-through assembly for a radio buoy

ABSTRACT

A water-tight antenna lead-through assembly which resists high pressures. The assembly comprises a tubular body surrounding a cylindrical plug. The plug is sealed to the tubular body by way of an O-ring residing in a groove in the surface of the plug. Cylindrical recesses are defined at each end of the plug, and associate with the base of an antenna. Another O-ring surrounds the antenna and resides in the cylindrical recess at the outermost end of the plug. Both of the cylindrical recesses are filled with a synthetic resin.

United States Patent 1 [111 3,882,499 Garito 1 May 6, 1975 1 1 ANTENNA LEAD-THROUGH ASSEMBLY 3.0s2,291 3/1963 Parkinson et a1 174/70 s FOR A RAD) BUOY 3,113,284 l2/l963 lnthoudt 174/77 R Inventor: Humbert Garito, Marseille, France Assignees: Le Nickel, Marseille; Centre National Pour IExploitation des Oceans, Paris; ERJI, Paris, France Filed: Oct. 23, 1973 Appl. No.: 408,520

[30] Foreign Application Priority Data Oct. 25, 1972 France N 72.37747 U.S. Cl. 343/709; 174/70 S; 174/77 R Int. Cl. H0lq l/34 Field of Search 343/904, 905, 906;

[56] References Cited UNITED STATES PATENTS 2,914,599 11/1959 Clarke et al. 174/70 S Primary Examz'nerEli Lieberman Attorney, Agent, or Firm-Fleit & Jacobson 5 Claims, 1 Drawing Figure [III] [1'11 ANTENNA LEAD-THROUGH ASSEMBLY FOR A RADIO BUOY This invention relates to a water-tight antenna leadthrough assembly which resists very high pressures, of the order of 600 bars. The invention is particularly intended for application to radio buoys used for marking, from a distance, the positions of underwater exploration devices.

It is known that, for the purpose of exploring seabeds, use is often made of exploration devices of the free-fall type, that is, devices which are launched from a ship to which they are not connected. Devices of this type, which include, for example, sampling instruments and sighting apparatus, are connected to floats and provided with sinkers which cause them to descend through the water. When the devices reach the seabed, automatic means, which will not be described here as they are not features of the present invention, cause the devices to carry out exploring operations and then release them from the sinkers so that they return to the surface of the water under the action of the floats.

Since the ship which launches these devices and which is usually also responsible for recovering them, is generally positioned at a considerable distance from the point at which the devices return to the surface, the devices are provided with means for marking their positions from a distance. Means of this kind include smoke-producing devices, flashing light generators, and radio buoys,

It is in this lastmentioned type of marking means that the antenna lead-through of the present invention is in tended to be applied. In particular, the problem to be solved is that of detachably mounting an antenna on the tubular body of a radio buoy so that the assembly is watertight at very great depths of immersion and, at the same time, is sufficiently robust to resist the impacts which almost inevitably occur when the exploration devices are operated.

it is an object of the present invention to overcome these difficulties and, according to the present invention, there is provided an antenna lead-through assembly for a Submersible radio buoy having a tubular body, the assembly comprising a plug fitted in the tubular body of the buoy, the plug having a tapered axial bore widening outwardly to receive the inner end part of the antenna which is of complementary shape and the plug having two generally cylindrical recesses formed one at the inner end and the other at the outer end thereof, a first toroidal seal interposed between the body and the plug. a second toroidal seal fitted around the antenna in the outer cylindrical recess, a filling of hardenable synthetic resin in each of the cylindrical recesses, a sleeve surrounding the antenna outwardly of the plug, a cap fitted on the plug to lie around the sleeve, means for securing the plug and the cap to the tubular body, and an electric conductor for connecting the antenna to a signal generator of the buoy.

The cap and the plug can be mounted on the tubular body of the buoy by any suitable means, but these parts are preferably secured to the body of the buoy by screws made of plastics material such as nylon.

The toroidal seal fitted between the plug and the tubular body of the buoy is preferably seated in an annular groove formed in the surface of the plug.

Furthermore, to provide an additional seat and to promote perfect adherence of the hardenable resin which is poured into the cylindrical recesses formed in the ends of the plug, the lateral surface of at least one of these recesses may contain an annular retaining groove.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing which is a fragmentary section through a submersible radio buoy in accordance with the invention.

The radio buoy partly shown in the drawing is designed to enable an emitter antenna 1 to radiate a highfrequency radio signal generated by means illustrated diagrammatically at 3 and connected to the antenna 1 by a conductor 2. The electrical circuitry and its electric battery (not shown) are accommodated in tubular body 9 of the buoy. The antenna 1 is preferably made of glass fibre and is provided with a central multi-strand core.

The water-tight fitting of the antenna 1 on the tubular body 9 is mainly achieved by means of a substantially axially-symmetrical plug 4 which is fitted in the body 9 by means hereinafter described, a toroidal seal 10 being interposed between the plug and the body. The plug 4 has an axial bore in which is fitted one end of the antenna 1; this bore, which is tapered, widens outwardly in the direction away from signal generator 3 as does the lower end length of the antenna, and the bore matches the shape of the antenna to establish a satisfactory seal. Furthermore, a cylindrical recess Sb is formed in the inner end of the plug 4 which is disposed within the buoy. The end of the antenna 1 projects into this recess 5b as does the conductor 2, and a mouldable synthetic resin poured into the seat 5b contributes to the water-tightness of the assembly as a whole and enables the antenna to be held even more securely in position.

A generally cylindrical recess 5a is formed in the outer end of the plug 4, which is disposed near the exterior of the buoy. A toroidal seal 6 surrounds the antenna l in this recess 5a into which a hardenable synthetic resin is likewise poured. The seal 6 then creates its own seat in the resin which, at the same time, ensures that the seal is bonded to the antenna. Furthermore, an annular retaining groove formed in the lateral surface of the recess 5a imparts additional watertightness and promotes optimum adherence in the assembly as a whole.

When the antenna 1 has thus been fitted in a rigid manner on the tubular body 9, a rubber sleeve 7 surrounded by a metal sleeve is passed over the free end of the antenna. The rubber sleeve 7 is clamped onto the plug 4 by means of a cap 8 which, with the plug 4, is secured to the body 9 by means of three screws 11 which are preferably made of a plastics material such as nylon. It will be appreciated that the function of the sleeve 7 is essentially that of reinforcing the base of the antenna 1 which is, in effect, weakened by being rigidly mounted in the plug 4.

Experience has shown that the antenna lead-through thus obtained prevents the ingress of water at depths of immersion of the order of 6000 metres, which corresponds to a pressure of around 600 bars. In addition, the assembly is sufficiently robust to resist the effects of violent impact.

What we claim is:

1. An antenna lead-through assembly for a submersible radio buoy having a tubular body, the assembly comprising a plug fitted in the tubular body of the buoy, the plug having a tapered axial bore widening outwardly to receive the inner end part of the antenna tapered to a complementary shape and the plug having two generally cylindrical recesses formed one at the inner end and the other at the outer end thereof, a first toroidal seal interposed between the body and the plug, a second toroidal seal fitted around the antenna and residing in the outer cylindrical recess, a filling of hardenable synthetic resin in the inner cylindrical recess. and a filling of hardenable synthetic resin in the outer cylindrical recess so as to cooperate with said recess and said second toroidal seal, a sleeve surrounding the an tenna outwardly of the plug, a cap fitted on the plug to lie around the sleeve, means for securing the plug and the cap to the tubular body, and an electric conductor for connecting the antenna to a signal generator of the buoy.

2. An antenna lead-through assembly according to claim 1, in which said sleeve is flexible and resilient.

3. An antenna lead-through assembly according to claim 2, in which said first toroidal seal is fitted in an annular groove formed in that part of said plug which extends into the tubular body of the buoy.

4. An antenna lead-through assembly according to claim 3, in which said plug and said cap are secured on the tubular body of the buoy by means of screws of plastics material.

5. An antenna lead-through assembly according to claim 4, in which at least one of said generally cylindrical recesses formed in the ends of the plug is provided with an annular retaining channel in its lateral surface. 

1. An antenna lead-through assembly for a submersible radio buoy having a tubular body, the assembly comprising a plug fitted in the tubular body of the buoy, the plug having a tapered axial bore widening outwardly to receive the inner end part of thE antenna tapered to a complementary shape and the plug having two generally cylindrical recesses formed one at the inner end and the other at the outer end thereof, a first toroidal seal interposed between the body and the plug, a second toroidal seal fitted around the antenna and residing in the outer cylindrical recess, a filling of hardenable synthetic resin in the inner cylindrical recess, and a filling of hardenable synthetic resin in the outer cylindrical recess so as to cooperate with said recess and said second toroidal seal, a sleeve surrounding the antenna outwardly of the plug, a cap fitted on the plug to lie around the sleeve, means for securing the plug and the cap to the tubular body, and an electric conductor for connecting the antenna to a signal generator of the buoy.
 2. An antenna lead-through assembly according to claim 1, in which said sleeve is flexible and resilient.
 3. An antenna lead-through assembly according to claim 2, in which said first toroidal seal is fitted in an annular groove formed in that part of said plug which extends into the tubular body of the buoy.
 4. An antenna lead-through assembly according to claim 3, in which said plug and said cap are secured on the tubular body of the buoy by means of screws of plastics material.
 5. An antenna lead-through assembly according to claim 4, in which at least one of said generally cylindrical recesses formed in the ends of the plug is provided with an annular retaining channel in its lateral surface. 